The present invention relates to liquid ophthalmic compositions for human and veterinary use comprising, inter alia, in an aqueous vehicle, a class of polyanionic polymers which, because of their unique combination of mucomimetic, rheological, and lubricating properties, are useful as long lasting, topically applied agents for relief of dry eye syndrome, foreign body sensation, burning, hyperemia, corneal staining, and the like. The ophthalmic compositions are also useful as lubricating and cushioning agents for the eye after traumatic injury or surgery. They may also be used as corneal wetting and lubricating agents for use with contact lenses, and in various eye irritation disorders.
The present invention also relates to a method of treating eyes by topically applying the ophthalmic solutions of the present invention when indicated for the relief of dry eye syndrome and when indicated to achieve the other effects mentioned above. Dry eye syndrome, and related eye ailments, including mere transitory discomforts, are well known in the scientific and patent literature. The following patents are incorporated herein by reference to the extent that they provide additional background on the syndrome and recognized indications for its relief: U.S. Pat. Nos. 4,039,662; 3,987,163; 3,920,810; 3,843,782; and 4,131,651; and Belgian Patent 844,544.
However, none of these prior art formulations meet all of the important criteria for an effective and long lasting treatment of dry eye syndrome, particularly the moderate to severe Kerato-conjunctivitis sicca (KCS) patient. These prior art attempts fall into three categories corresponding to their physical state: liquids, anhydrous ointments, and solids. The solids are in the form of ocular inserts which slowly dissolve or erode to provide a thickened tear film. While these have the potential for providing longer term symptomatic relief than liquids, few patients are willing to persist in using them since they are difficult to insert and, once in place, tend to be uncomfortable, frequently themselves causing the foreign body sensation they were meant to treat. Prior liquid and ointment formulations, while giving the sensation of relief, are strictly palliatives without long-term effect.
Thus, the search for an easy to use (especially by infirmed patients via self-medication), long lasting (4 to 24 hours) ophthalmic preparation for treating the effects described collectively under the dry eye syndrome and having the ancillary utilities mentioned above continues.